@SpringBootApplication
is a convenience annotation that adds all of the following:
-
@Configuration
: Tags the class as a source of bean definitions for the application context. -
@EnableAutoConfiguration
: Tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings. For example, ifspring-webmvc
is on the classpath, this annotation flags the application as a web application and activates key behaviors, such as setting up aDispatcherServlet
. -
@ComponentScan
: Tells Spring to look for other components, configurations, and services in thecom/example
package, letting it find the controllers.
The main()
method uses Spring Boot’s SpringApplication.run()
method to launch an
application. Did you notice that there was not a single line of XML? There is no web.xml
file, either. This web application is 100% pure Java and you did not have to deal with
configuring any plumbing or infrastructure.